Cryotreatment may be used to treat a variety of conditions, such as atrial fibrillation, tumor treatment, and others. Generally, cryotreatment involves circulating a refrigerant from a refrigerant source through one or more fluid delivery conduits and into the cryotreatment device, wherein the refrigerant expands and cools a portion of the cryotreatment device to treatment temperatures. The cryotreatment device may be in fluid communication with a vacuum source that facilitates removal of expanded refrigerant from the cryotreatment device and through one or more fluid recovery conduits.
Cryotreatment devices may develop leaks, which not only impacts cooling efficiency but also threatens patient welfare. Many devices include a leak detection mechanism at some location within a fluid pathway that can be used to detect a fault (for example, a fluid leak within the device or blood ingress) and alert the user. In some cases, fluid delivery is stopped and/or the vacuum source is inactivated to help ameliorate the condition. However, the leak detection mechanism may communicate a false positive fault condition to the user. In such a case, the procedure delay caused by the system shutdown not only extends the time required for the medical procedure, but frequent system shutdowns may cause excessive mechanical or electrical wear on the system.
Currently known fault-detection mechanisms include a driver that sends a signal along an electrical pathway in which a detector is placed at the other end of a normally open circuit. If blood or fluid enters the system, the fault-detection mechanism identifies a fault condition. However, false detection of a fault condition may be caused by external sources, such as electromagnetic interference with the detection line. Such interference is frequently encountered when using a medical device including a leak-detection mechanism is used for electrophysiology procedures, especially where certain mapping or ablation equipment is in use (for example, Carto-3 mapping systems). Although some workarounds may be available, these are inconvenient and many are not well known, especially by less-experienced users.
It is therefore desired to provide a fault-detection method, system, and device for a cryosurgical system that avoids false-positive fault detection.